Vehicle speed control device

ABSTRACT

A railroad car maximum speed limiting device including a railroad car wheel-driven generator and centrifugal speed responsive switch for operating a solenoid to supply air pressure to the vehicle brakes after the vehicle has passed a magnetic trip operating a relay means to complete the generator circuit, the improvement comprising an air cylinder operated by trainline pressure for moving the generator and centrifugal speed responsive switch wheel out of engagement with the car wheel for trainline operation, and a shuttle valve for supplying alternately braking air pressure from the speed control reservoir or from the conventional pressurized air reservoir, and means for adjusting the speed at which the centrifugal speed responsive switch will operate.

United States Patent 1,793,589 2/1931 Dapronetal 303/2l(CF) 3,370,1662/1968 DaRoldetal 246/l82(B) Primary Examiner-Arthur L. La PointAssistant Examiner-George H. Libman Attorneys-Hilmond O. Vogel and WayneMorris Russell ABSTRACT: A railroad car maximum speed limiting deviceincluding a railroad car wheel-driven generator and centrifugal speedresponsive switch for operating a solenoid to supply air pressure to thevehicle brakes after the vehicle has passed a magnetic trip operating arelay means to complete the generator circuit, the improvementcomprising an air cylinder operated by trainline pressure for moving thegenerator and centrifugal speed responsive switch wheel out ofengagement with the car wheel for trainline operation, and a shuttlevalve for supplying alternately braking air pressure from the speedcontrol reservoir or from the conventional pressurized air reservoir,and means for adjusting the speed at which the centrifugal speedresponsive switch will operate.

mama] JUN awn 3584214 lnven'ror wllllqm H.Peferson Attorney mama] JUN8L9?! 31584214 sum 2 OF 4 a l E W I I l mm H Peterson Attorney 'PATENTEUJUN 8 Ian 3,584,214 SHEET 3 OF 4 78a I 78c d 200 F 2o L 1 InventorWilliam H. Peterson Attorney VEHICLE SPEED CONTROL DEVICE It is ageneral object of this invention to provide an improved speed controldevice which is rendered inoperative during trainline operation andwhich shall provide alternate sources of air pressure for braking or notbraking the vehicle in accordance with classification yard or trainlineoperations and also to provide for a speed control device which may beadjustable to operate at the different speeds.

It is further an avowed purpose of this invention to provide for a newand improved speed control device for a railroad car in theclassification yard where the free rolling speed of the railroad car iscontrolled or limited to a specific impact speed, for example, three orfour miles per hour, by having the railroad car pass by a magnet fortripping an on vehicle magnetically operated reed switch to operate arelay to complete an electric circuit having its electricity supplied bythe generator operated by the rolling of the car and a car wheel drivencentrifugal switch operable in excess of the desired speed to completethe circuit for energizing a solenoid valve supplying air pressure tobrake the vehicle speed, the speed control device being made inoperativeduring trainline operations and means controlling the sensitivity ofoperation of the speed control device at a particular speed, and wherebyair pressure may alternately be supplied by a special tank for speedcontrol operation or by the customary air pressure tank on the vehiclethat is in use during trainline operation.

These and other objects, purposes and advantages will become apparent byreference to the following description, attached drawings and appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial view of a railroadhopper car employing the subject invention;

FIG. 2 is an enlarged partial view of FIG. 1 illustrating the magneticpickup or switch device and generator of the invention;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 showing themagnetic pickup device and generator and centrifugal switch unit in anoperative position;

FIG. 3A is a view similar to FIG. 3 but showing the magnetic switchdevice and generator and centrifugal switch unit in an out-of-useposition;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is an exploded view of the arrangement of various components ofthe speed control device;

FIG. 6 is a partial sectional view taken along line 6-6 of FIG. 3; and

FIG. 7 is a schematic diagram showing the electrical-pneumatic circuitryof the various operational components of the speed control device.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to thedrawings and in particular with reference to FIG. 1, there is shown apartial view or end portion of a railroad hopper car with the usualhopper 3 and end structure 4, coupler means 5 and center sill means 6,truck means 7 with truck frame 8 and wheels 9. The end deck portion 10of the hopper car carries the pressurized fluid or air in a reservoirtank 11 and the vehicle brake cylinder 12 operating brake rigging 13 forapplying the brakes (not seen) to the vehicle 2.

The speed of the rolling car or vehicle within a classification yard iscontrolled by a speed control device operative on the vehicle brakes,the operation and general arrangement of said device 15 being generallyshown and described in my copending US. Pat. application, Ser. No.694,447 filed Dec. 29, I967, which is incorporated herein by reference.

The speed control device is provided with a magnetic responsive switchmeans 14 mounted on the end portion of the truck frame 8 and so placedadjacent the rail means 150 as to be influenced magnetically by magnetor off-vehicle conditioning or tripping means 16 (carried by bracket 16amounted on rail 15a) of the device 15 as the car moves by the magnet 16as more clearly seen in FIGS. 2, 3, 6 and 7. The speed control device isfurther provided with a railroad car wheel-driven generator means 17which is a direct current generator with a permanent magnet field and arailroad car wheel-driven centrifugal speed responsive switch means 18.The speed control device is further provided with a relay means orstarter means 20 and a solenoid valve means 21, as seen in FIG. 7. Thegenerator 17, the speed responsive or switch means 18, the relay means20 and the solenoid valve means 21 are all in series in the electricalcircuit 22 such that when the switch means 18 closes the circuit 22 andthe relay means 20 is in the energized condition the solenoid valvemeans 21 is opened to allow air under pressure from the additionalreservoir tank 11 to go to the brake cylinder means 12 for applying thevehicle brakes. The relay means 20 is energized to complete the circuit26, when there is sufficient electric current generated by the generator17 due to sufficient movement of the vehicle or car. The relay means 20will be energized when the magnet means 16 actuates the magneticresponsive reed switch or relay actuating switch to close magnetic drawncontact 14a against contact 14b to complete the holding series circuit23 which includes the generator, the switch 14 and the magnetl6 and therelay means 20. The relay means 20 includes the relay coil 20a andplunger 20b from moving contacts 20c and 20d for closing circuit 22. Thecontact arm 18a of the switch means 18 comes in contact with electricalcontacts 18b and of circuit 22 when the vehicle speed exceeds 4 mph. tocomplete the circuit 22 at that point. The generator 17 is driven by thedrive means 24 which also drives the switch means 18. The drive means 24includes the railroad wheel engaging drive wheel or gear 25 which drivesthe generator shaft part 26 and the centrifugal speed responsive switchoperating shaft 27 extending from the shaft part 26 and constrained formovement therewith. Rotation of shaft part 26 operates the generator I7to supply the necessary current to operate the speed control device andshaft part 27 operates the centrifugal device or switch means 18 bythrowing weights 28 and 29 radially outwardly to cause switch means endpart 30 to engage button 31 of switch element 32 to complete the circuitat the centrifugal speed responsive switch for energizing the solenoidvalve 21 by electrical conduit means 33, see FIG. 4.

As best seen in FIG. 5, the generator 17 and the centrifugal switchmeans 18 are contained within a common housing 34 of the generatorcentrifugal switch unit 19 which is carried by saddle structure ormounting bracket unit 35 which comprises a U-shaped portion 36 fittingaround the housing 34 and a closure plate or clamp portion 37 with bolts38 holding the parts 36 and 37 together around the housing 34, theinteriors of each part 36 and 37 having arcuate cushioning pad portions40 and 41 respectively for embracing the housing 34 and relieving sameagainst shock loading. The mounting part 37 of g the bracket means 35 isfixed on the generator-centrifugal speed responsive switch carriage arm43. The arm 43 has provided at its lower end a journal portion 44 forreception of stub shaft 45 of the mounting bracket unit 46. The bracketunit 46 has a horizontal plate 47 and an upright shoulder 48 forengaging against the depending arm portion 49 and held thereto by boltmeans 47a (see FIG. 2) of the truck frame 8. i

The bracket element 46 is provided with a horizontally outwardlyextending L-shaped arm 50 which carries a clevis structure 51 at theouter end thereof for reception of an arm 52 held thereto by means ofpin 53, as seen in FIG. 5. The arm 52 forms part of the pressurizedfluid or air cylinder or power, unit 54 which consists of a cylinder 55and an internal piston head 56 resiliently urged inwardly by spring 57,the piston head being carried on plunger stem 58 of plunger member orram 59 which is movable with respect to the cylinder 55, the arm 52being fixed with respect to the cylinder 55. The power or drive cylindermeans 54 moves the generator and speed responsive switch unit 19 betweenoperative and inoperative positions.

The hollow stub shaft 45 (received in bracket 46) has a hollow bore 60and is extendable into the journal 44 of the arm structure 43 as isreadily apparent from the exploded view of FIG. 5. A coupling element 61has a shaft 62 extendable through the aperture 60 in the assembledcondition of the elements 46 and 43 (held together with nut means 62a)and has a coupled journal portion 63 receiving the arm 64 (held to part63 by setscrew 63a) of the magnetic pickup relay means 14. The arm 64and thus magnet switch means 14 is fixed with respect to truck frame 8.The arm 64 is hollow for receiving electrical wires 65 which terminatein a reed switch arrangement 14 including an upper contact arm 14a whichis magnetresponsive and a lower contact arm 14b which will have theupper arm 14a drawn to it by magnet 16 when passing thereby in order tocomplete the electrical circuit 23 through connecting together of wiring65. The reed switch elements 14a and 14b are contained in the lower orhead portion 69 of the mechanism 14. The generator-centrifugal speedresponsive switch unit 19 and the magnetic pickup means 14, as seen byFIG. 5, are all carried by the bracket structure 35, 63, 64, 43 and 46and the air cylinder 54 has its fixed end 52, as previously mentioned,coupled to journal 51 and the free end or plunger 59 is pivotallyconnected by its trunnion 59a to arm 59b carried by element 37 whichallows for movement of the generator-centrifugal switch unit 19 toselectively permit engagement and disengagement of the wheel 25 with thecar wheel 9 due to pivotal movement of the am 43 at itsjournaled means44 about shaft portions 45. The engaged position of the wheel 25 withthe wheel 9 and the positioning of the pickup unit 14 over the rail aand associated magnet 16 is seen in FIG. 3. FIG. 3a on the other handshows the position of the generator-centrifugal switch unit 19 out ofengagement with the wheel 9. As stated, the power unit or air cylindermeans 54 moves the generator-centrifugal switch unit 19 from operativeto inoperative position, i.e., from classification yard operation to intrainline operation (when the air trainline 70, see FIGS. 1 and 7, iscoupled to the trainline of an adjacent standing car of a train for roadoperation) and air under pressure is thereby introduced into thetrainline 70 and into air hose 71 (see FIGS. 3 and 7) to supply airunder pressure to the air cylinder means 54 for operating same to swingthe generator-centrifugal switch unit 19 away from the car wheel.

Now, with reference to FIG. 7, it is seen that the pneumatic circuit 73is coupled with the electrical circuit through the solenoid operated airsupply valve 21. The pneumatic circuit 73 includes the air cylindermeans 54 for placing the generator switch structure in operative andinoperative positions, and includes the main air reservoir 74 as used onconventional cars supplied with pressurized air from the line 70, aswell as the additional reservoir 11 and check valve 76 directing theflow one way to the reservoir 11. A conventional AB valve 77 is disposedbetween the main reservoir 74 and the two-way or sliding free pistonvalve unit 78. Line 70 connects with the reservoir 11 by way of line 76aand with the AB valve 77 by way of line 77b. The AB valve 77 connectswith the main reservoir (auxiliary reservoir and emergency reservoirunit) 74 by way of lines 770 and 77a and connects with the twoway valvemeans 78 by way of line 780. A pressure-responsive dump valve orpressure relief (exhaust) valve 80 for exhausting the air to theatmosphere by way of line 81. connects with the solenoid valve 21 by wayof line 82 and with the two-way valve 78 by way of line 83, the solenoidvalve 21 connecting with the additional or solenoid valve supplyreservoir 11 by line 75. The pneumatic operation of the system 73 is asfollows. The additional air supply or reservoir 11 is filled or chargedwith air as is the main reservoir 74 when the trainline 70 is coupledwith another car for over-the-road or in trainline operation which isstandard operating procedure for charging of the main reservoir 74. Whenthe trainline 70 is in a disconnect position so that the car 2 is byitself and in a free rolling state having passed a hump in aclassification yard, the magnet 16 acts upon the relay actuating or reedswitch means 14 to energize the relay to complete the circuit to thegenerator.

Next, the switch means 18 completes the circuit to energize the solenoidvalve means 21 when the railroad car is rolling at speeds of 4 m.p.h. orin excess thereof. Then air under pressure passes from the additionalreservoir 11 through the solenoid valve 21a which is now in theenergized or opened position through lines 75, 82 and through thepressure-responsive valve 80, through line 83 and into valve 78 to movethe sliding free piston 78a to allow the pressurized air to pass intoconduit 78b and to the brake cylinder 12 for applying the vehicle brakesto slow down the car. The valve 78 thus serves to isolate the brakecylinder 12 from the existing conventional AB valve 77 and mainreservoir 74 when the speed control device is in use. Once the speed ofthe car has fallen below the predetermined speed of 4 mph. the switchmeans 18 breaks the circuit and deenergizes the solenoid valve 21allowing the valve 210 to cut off the supply of pressurized air fromreservoir 11 to the valve means 78. Then air bleeding through air bleedopening 84 in line 82 causes a drop in pressure across the diaphragm ato have diaphragm spring 80b raise the diaphragm 80a to permit air inthe brake cylinder 12 to dump past valve seat 800 and to atmosphere tube80d to rapidly exhaust the pressurized air to the atmosphere forremoving application of the vehicle brakes to the vehicle wheel. Duringtrainline operations when the solenoid valve means 21 is deenergized,air under pressure can only come from the main reservoir 74 via the ABvalve 77 and through line 780 into the chamber 78b to move the slidingfree piston 78a to a position to permit the air under pressure tocommunicate with line 78d and not with line 83. The supply of air underpressure from the main reservoir via the AB valve to the brake cylinderis conventional operation.

The amount of distance that the element 30 must travel in order toengage the element 31 of the switch 32 may be adjustable by the switchadjustment means which includes setscrew 91 and nut 92 mounted on arm 93held to the back plate 94 of the housing 34, the arm 93 pivotallycarrying arm 95 biased against the screw 91 by spring 96 held byretainer 97 mounted to the housing 34. Extension of the screw 91inwardly swings the arm 95 inwardly or counterclockwise about pivot 98against the action of the spring 96 to insure an earlier contact betweenswitch contact portions 30 and 31 and therefore a lesser vehicle speedwould be required to operate the speed control device; whereas if thescrew 91 is moved out wardly the arm 95 carrying the switch 31 isremoved further from contact part 30 requiring therefore a greaterdistance for arm 30 to travel and therefore a greater vehicle speedwould be required for the speed control device to operate.

A flow control valve means 90 is placed in line 71 between the trainline70 and the air cylinder means 54. The flow control valve means 90 has acheck valve 90b between chambers 90a and 90a to permit flow from thetrainline 70 to the air cylinder means 54 but not in the reverse way.The valve means 90 is further provided with an adjustable means 90d inthe form of a tapered setscrew adjustable in and out of a taperedthreaded opening 900 between chambers 90a and 90a to allow flow fromchamber 90a to 90a via the bleed orifice 90c which is a restricted floworifice. As stated, during train operation, pressure is maintained inthe cylinder means 54 to keep the speed control unit 15 out ofengagement with the car wheel. During emergency brake applications, suchas if the car is going 70 mph. and the brakes are applied, the pressurein the trainline 70 drops to practically zero and if it were not for theflow control means 90, the fluid pressure would also drop to zero in thecylinder means 54 causing immediate engagement of the wheel 25 of thespeed control device with the wheel 9 of the car. At speeds of 70 mph.the generator means 17 would be operated at such high revolutions perminute that the unit 17 could be damaged. The flow control means 90permits the air in the line 71 to gradually drop because of therestriction afforded by the adjustable screw 90d and its orifice 90c sothat, say, for a period of 5 minutes the pressure in the cylinder means54 is not sufficiently low enough to allow engagement of its wheel 25with the wheel 9, thus permitting the speed of the train to drop, say,to mph. before engagement of wheel 25 with the wheel 9 and consequentlyavoiding any damage to the generator which will now be operated at amuch lower speed.

The foregoing description and drawings are given merely to explain andillustrate the invention, and the invention is not to be limited theretosince those skilled in the art who have the disclosure before them willbe able to make modifications and variations therein without departingfrom the scope of the invention.

What I claim is:

1. A speed control device for a railroad car to control the speed of thecar within predetermined limits comprising:

a wheel driven governor,

speed control valve means to supply fluid under pressure to anassociated car brake cylinder for operating the associated car wheelbrakes and operatively associated with said governor and opened therebyupon exceeding a predetermined maximum speed for supplying the fluidunder pressure to the brake cylinder,

conditioning means operatively connected with said speed control valvemeans and the governor and selectivelycontrolling the operation of saidvalve means in accordance with the speed of the car,

off-car mounted tripping mechanism being operatively associated withsaid conditioning means to operate same and to set the conditioningmeans to cause a supply of pressurized fluid to said speed control valvemeans when required,

said governor comprising a speed responsive unit operable in accordancewith the predetermined maximum speed of the car to cause operation ofthe valve means, and mounting means pivotally mounting the speedresponsive unit on the car for movement of the speed responsive unitbetween operative and inoperative positions.

2. The invention according to claim 1, and said device including a wheeldriven generator connecting with the speed responsive unit and the valvemeans and operative upon the latter when a predetermined speed isexceeded to brake the car.

3. The invention according to claim 1, and movable means for moving saidmounting means between operative and inoperative positions.

4. The invention according to claim 3, and said movable means includinga fluid operated ram means which, upon extension and contraction inresponse to the fluid under pressure, moves said mounting means and saidspeed responsive unit thereby between said operative and inoperativepositions.

5. The invention according to claim 4, and means having a source ofpressure introduced to said fluid operated ram means for moving thespeed responsive unit to the inoperative position.

6. The invention according to claim 1, and said speed responsive unitcomprising a centrifugal speed responsive switch.

7. The invention according to claim 1, and said speed responsive unitcomprising a centrifugal speed responsive switch,

generator means being operated by the movement of said car and operativeto supply a source of electrical energy to said speed control valvemeans when said centrifugal speed responsive switch closes the circuitbetween the speed responsive control valve means and the generator.

8. A speed control device for a railroad car to control the speed of thecar within predetermined limits comprising:

a wheel driven means and a governor driven by said wheel means,

speed control valve means to supply fluid under pressure to anassociated car brake cylinder for operating the associated car wheelbrakes and operatively associated with said governor and opened therebyupon exceeding a predetermined maximum speed for supplying the fluidunder pressure to the brake cylinder,

conditioning means operatively connected with said speed control valvemeans and the governor and selectively controlling the operation of saidvalve means in accordance with the speed of the car, I off-car mountedtripping mechanism being operatively associated with said conditioningmeans to operate same. and to set the conditioning means to cause asupply of pressurized fluidto said speed control valve means whenrequired, and pneumatic means including a first reservoir, a secondreservoir, passage means supplying fluid to each reservoir, conduitmeans connecting with each of the reservoirs for supplying braking fluidto the brake cylinder, said conduit means including a first conduitconnecting with the speed control valve and with the first reservoir anda second conduit connecting with the second reservoir, two-way valvemeans adapted for connecting with the associated brake cylinder andconnecting with each of the conduits, and means in said two-way valvemeans for selectively and alternately supplying communication betweenone of. the conduits and the brake cylinder, said governor uponoperating of said speed control valve means allowing communication ofthe first conduit with the brake cylinder and preventing communicationof the second conduit with the brake cylinder. 9. The inventionaccording to claim 8, and said two-way valve means having a portcommunication with the first con-, duit and having a port communicationwith the second conduit and having a port communication with the brakecylinder and passage blocking means reciprocally disposed in said two-'-way valve and movable in response to pressure in either the first orsecond conduit for moving the passage blocking means to the otherposition for communication of the other conduit with the brake cylinder.

10. The invention according to claim 8, and a quick exhaust valve beingdisposed between the speed control valve means and the two-way valvemeans and bleed hole means operatively associated with and operativeupon the first conduit for dropping the pressure therein and exhaustingfluid under pressure from the associated brake cylinder and out thequick exhaust valve means.

11. The invention according to claim 10, and said quick ex haust valvemeans including a resiliently loaded diaphragm operable to exhaust thefluid from the brake chamber upon a drop in pressure in the firstconduit.

12. A speed control device for a railroad car to control the speed ofthe car within predetermined limits comprising:

a wheel driven governor, speed control valve means to supply fluid underpressure to an associated car brake cylinder for operating associatedcar wheel brakes and operatively associated with said governor andopened thereby upon exceeding a predetermined maximum speed forsupplying the fluid under pressure to the brake cylinder, conditioningmeans operatively connected with said speed control valve means and thegovernor and selectively controlling the operation of said valve meansin accordance with the speed of the car,

off-car mounted tripping mechanism being operatively associated withsaid conditioning means to operate same and to set the conditioningmeans to cause a supply of pressurized'fluid to said speed control valvemeans when the predetermined speed is exceeded, said speed control valvemeans including an electrical solenoid valve and said governor includinga centrifugal speed responsive switch and an electrical generator forsupplying current, the generator and switch being drivingly operated byengagement with the railroad wheel whereby an electrical current issupplied to the solenoid valve for energizing the same upon closing ofthe switch when the vehicle reaches a predetermined speed,

said switch including a first fixed contact portion and a second movableswitch portion movable toward the first fixed portion upon increase incar speed, and

means for movably adjusting the fixed contact portion with respect tothe movable portion for variably adjusting the maximum car speedrequired to energize the solenoid valve.

13. The invention according to claim 12, and said variable adjustablemeans providing a setscrew means for movement of the fixed contactportion toward and away from the movable switch portion.

14. A speed control device for a railroad car to control the speed ofthe car within predetermined limits comprising:

a wheel driven governor including a speed responsive means,

speed control valve means to supply fluid under pressure to anassociated car brake cylinder for operating associated car wheel brakesand operatively associated with said governor and opened thereby uponexceeding a predetermined maximum speed for supplying the fluid underpressure to the brake cylinder,

conditioning means operatively connected with said speed control valvemeans and the governor and selectively controlling the operation of saidvalve means in accordance with the speed of the car,

off-car mounted tripping mechanism being operatively associated withsaid conditioning means to operate same and to set the conditioningmeans to cause a supply of pressurized fluid to said speed control valvemeans when required,

a wheel driven generator, and

mounting means carrying said speed responsive means and said generatorand being pivotal between an engaged position for operation of the speedcontrol device in a speed control position and in a position where saidspeed control device is inoperative.

15. The invention according to claim 14, and movable means connectingwith the mounting means and moving same for pivoting said generator andsaid speed responsive means between operative and inoperative positionsof the speed con trol device.

16. A speed control device for a vehicle comprising:

an electric circuit,

an electric generator in said circuit and for mounting on the car andoperatively connectable with the vehicle wheel and drivable thereby,

a speed responsive switch in said circuit and operatively connectablewith said wheel and drivable thereby to complete the electric circuit tothe generator in going from an open position to a closed position whenthe vehicle exceeds a predetermined speed,

an off-vehicle trigger responsive switch element in said circuit havingopened and closed circuit positions and mountable on said vehicle andconnecting with the generator,

a holding relay in said circuit being in series connection with saidswitch element and said generator whereby when said switch element is inthe closed position said holding relay is energized, said holding relaybeing mountable on said vehicle,

a solenoid actuated air valve for supplying and terminating the supplyof air pressure to the associated vehicle brakes being in said circuitand having a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle,

said speed responsive switch, in going from the open to the closedposition upon the vehicle's exceeding a predetermined speed, causes thesolenoid valve to be placed in a closed circuit series connection withthe generator with the holding relay being energized whereby thesolenoid valve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brakes, and

mounting means carrying said speed responsive switch and said generatorand being pivotal between an engaged position for operation of the speedcontrol device in a speed control position and in a position where saidspeed control device is inoperative.

17. A speed control device for a vehicle comprising:

an electric circuit,

an electric generator in said circuit and for mounting on the vehicleand operatively connectable with the vehicle wheel and drivable thereby,

a speed responsive switch in said circuit and operatively connectablewith said wheel and drivable thereby to complete the electric circuit tothe generator in going from an open position to a closed position whenthe vehicle exceeds a predetermined speed,

an off-vehicle trigger responsive switch element in said circuit havingopened and closed circuit positions and mountable on said vehicle andconnecting with the generator,

a holding relay in said circuit being in series connection with saidswitch element and said generator whereby when said switch element is inthe closed position said holding relay is energized, said holding relaybeing mountable on said vehicle,

a solenoid actuated air valve for supplying and terminating the supplyof air pressure to the associated vehicle brakes being in said circuitand having a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle,

said speed responsive switch, in going from the open to the closedposition upon the vehicles exceeding a predetermined speed, causes thesolenoid valve to be placed in a closed circuit series connection withthe generator with the holding relay being energized whereby thesolenoid valve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brake means, and

pneumatic means including a first reservoir, a second reservoir, passagemeans supplying fluid to each reservoir, conduit means connecting witheach of the reservoirs for supplying braking fluid to the brakecylinder, said conduit means including a first conduit connecting withthe speed control valve and with the first reservoir and a secondconduit connecting with the second reservoir, two-way valve meansadapted for connecting with the associated brake cylinder and connectingwith each of the conduits, and means in said two-way valve means forselectively and alternately supplying communication between one of theconduits and the brake cylinder, said solenoid valve allowingcommunication of the first conduit with the brake cylinder andpreventing communication of the second conduit with the brake cylinderwhen the vehicle exceeds the predetermined speed.

18. A speed control device for a vehicle comprising:

an electric circuit,

an electric generator in said circuit and for mounting on the vehicleand operatively connectable with the vehicle wheel and drivable thereby,

a speed responsive switch in said circuit and operatively connectablewith said wheel and drivable thereby to complete the electric circuit tothe generator in going from an open position to a closed position whenthe vehicle exceeds a predetermined speed,

an off-vehicle trigger responsive switch element in said circuit havingopened and closed circuit positions and mountable on said vehicle andconnecting with the generator,

a holding relay in said circuit being in series connection with saidswitch element and said generator whereby when said switch element is inthe closed position said holding relay is energized, said holding relaybeing mountable on said vehicle,

a solenoid actuated air valve for supplying and terminating the supplyof air pressure to the associated vehicle brakes being in said circuitand having a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle,

said speed responsive switch, in going from the open to the closedposition upon the vehicle's exceeding a predetermined speed, causes thesolenoid valve to be placed in a closed circuit series connection withthe generator with the holding relay being energized whereby thesolenoid valve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air' supply to the vehicle brakes,

said switch including a first fixed contact portion and a second movableswitch portion movable toward the first fixed portion upon increase invehicle speed, and

means for movably adjusting the fixed contact portion with respect tothe movable portion for variably adjusting the maximum vehicle speedrequired to energize the solenoid valve.

19. A speed control device for a vehicle comprising:

an electric circuit,

an electric generator in said circuit and for mounting on the vehicleand operatively connectable with the vehicle wheel and drivable thereby,

a speed responsive switch in said circuit and operatively connectablewith said wheel and drivable thereby to complete the electric circuit tothe generator in going from an open position to a closed position whenthe vehicle exceeds a predetermined speed,

an off-vehicle trigger responsive switch element in said circuit havingopened and closed circuit positions and mountable on said vehicle andconnecting with the generator,

a holding relay in said circuit being in series connection with saidswitch element and said generator whereby when said switch element is inthe closed position said holding relay is energized, said holding relaybeing mountable on said vehicle,

a solenoid actuated air valve for supplying and terminating the supplyof air pressure to the associated vehicle brakes being in said circuitand having a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle,

said speed responsive switch, in going from the open to the closedposition upon the vehicle's exceeding a predetermined speed, causes thesolenoid valve to be placed in a closed circuit series connection withthe generator with the holding relay being energized whereby thesolenoid valve is moved for supplying air pressure to brake the vehicle,whereupon the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brakes, and

mounting means for said speed responsive switch forattaching the speedresponsive means to the vehicle, said mounting means being pivotalbetween an engaged position for operation of the speed control device ina speed control position and having a position where said speed controldevice is ineffective.

20. The invention according to claim 19, and means for pivotally movingsaid mounting means between operative and inoperative positions.

21. The invention according to claim 20, and said means for movingincluding a pneumatically operated ram and cylinder jack means.

22. In a railroad vehicle having a frame structure and having groundengaging means, a vehicle speed control device com prising: 3

a ground driven generator provided with shaft means driven by therotation of said ground engaging means,

vehicle mounted solenoid operated fluid supply valve,

centrifugal speed responsive means operably engageable with said shaftmeans and operable upon a predetermined rotational speed of said groundengaging means for operably coupling said generator with the vehiclesolenoid operated fluid supply valve for operating the latter to supplyand terminate fluid under pressure to the associated vehicle brake meansfor operation thereof when the predetermined speed is exceeded,

starter means operatively connected with said generator and said supplyvalve and operated by associated ground mounted energizing means toprepare for operation of said speed control device, and i means mountedon said vehicle frame structure and carrying said generator to and fromoperable engagement with said ground engaging means.

23. The invention according to claim 22, and said means mounted on saidvehicle frame structure further operatively carrying said centrifugalspeed responsive means for moving said starter means from inoperable tooperable position with respect to the ground engaging means and beingmounted on said vehicle frame structure. \v

24. The invention according to claim 22, and said centrifu gal speedresponsive means including adjustment means for varying thepredetermined speed at which the speed respon-- sive means is operative.

25. The invention'according to claim 22, and said centrifut gal speedresponsive means including an electrical switch being provided withcentrifugal weight means adapted to move the switch to a closed positionupon an increase in vehi-l cle speed. i

26. The invention according to claim 25, and adjustment means mounted onsaid centrifugal switch and including an adjustable set member fixedlymounted on the switch andai gal speed responsive means being carried bysaid frame and being placed from operative to inoperative position alsoupon a change in pressure in said ram unit.

30. The invention according to claim 22, and pneumatic means forsupplying the pressure fluid to said brake cylinder including a firstreservoir for supplying fluid pressure by way of the solenoid valve tosaid brake cylinder and a second reser-, voir for supplying pressurizedfluid to the brake cylinder via an associated second valve,

flow control means in the form of a two-way valve including meansresponsive to fluid pressure from the solenoid valve or from the secondvalve to supply selectively pres- I surized fluid to the brake cylinder,said means including a flow blocking valve member movable in onedirection by the solenoid valve and in the other direction by the secondvalve.

31. The invention according to claim 30, and a valve struc-. ture forsupplying the pressurized fluid to a low pressure area. including ableed valve hole adjacent the solenoid valve and pressure responsivediaphragm valve movable to exhaust the air to the low pressure area whenpressurized fluid is blocked by the two-way valve between the solenoidvalve and the brake cylinder.

32. The invention according to claim 22, and said means mounted on saidvehicle frame structure comprising an arm extending from said framestructure downwardly adjacent the ground, said arm carrying at its lowerend said starter means for placing the starter means adjacent theassociated ground mounted energizing means.

33. The invention according to claim 32, and said starter meansincluding a magnetically responsive switch energizable by said groundmounted energizing means, and

relay means operable upon closing of said switch to connect thegenerator with the solenoid operated valve when the predeterminedvehicle speed is exceeded.

34. The invention according to claim 1, and said mounting means havingflow control means including one-way flow means for actuation of saidspeed control device into an operative position, and

bleed means in said flow control means for deactivating operation ofsaid speed control device.

35. The invention according to claim 5, and flow control means betweensaid ram means and a source of fluid pressure,

said flow control means including a one-way valve permitting flow fromthe source of pressure to the ram means for moving said speed responsiveunit to the inoperative position and including orifice means to allowescape of fluid under pressure from said ram means to said source ofpressure in the other direction to place the speed responsive unit inthe operative position.

36. The invention according to claim 16, and said mounting means havingflow control means including one-way flow means for actuation of saidspeed control device into an operative position, and

bleed means in said flow control means for deactivating operation ofsaid speed control device.

37. The invention according to claim 20, and said means for pivotallymoving said mounting means having flow control means including one-wayflow means for actuation of said speed control device into an operativeposition, and

bleed means in said flow control means for deactivating operation ofsaid speed control device.

38. The invention according to claim. 2l, and flow control means betweensaid ram means and a source of fluid pressure,

said flow control means including a one-way valve permitting flow fromthe source of pressure to the ram means for moving said speed responsiveunit to the inoperative position and including orifice means to allowescape of fluid under pressure from said ram means to said source ofpressure in the other direction to place the speed responsive unit inthe operative position.

1. A speed control device for a railroad car to control the speed of thecar within predetermined limits comprising: a wheel driven governor,speed control valve means to supply fluid under pressure to anassociated car brake cylinder for operating the associated car wheelbrakes and operatively associated with said governor and opened therebyupon exceeding a predetermined maximum speed for supplying the fluidunder pressure to the brake cylinder, conditioning means operativelyconnected with said speed control valve means and the governor andselectively controlling the operation of said valve means in accordancewith the speed of the car, off-car mounted tripping mechanism beingoperatively associated with said conditioning means to operate same andTo set the conditioning means to cause a supply of pressurized fluid tosaid speed control valve means when required, said governor comprising aspeed responsive unit operable in accordance with the predeterminedmaximum speed of the car to cause operation of the valve means, andmounting means pivotally mounting the speed responsive unit on the carfor movement of the speed responsive unit between operative andinoperative positions.
 2. The invention according to claim 1, and saiddevice including a wheel driven generator connecting with the speedresponsive unit and the valve means and operative upon the latter when apredetermined speed is exceeded to brake the car.
 3. The inventionaccording to claim 1, and movable means for moving said mounting meansbetween operative and inoperative positions.
 4. The invention accordingto claim 3, and said movable means including a fluid operated ram meanswhich, upon extension and contraction in response to the fluid underpressure, moves said mounting means and said speed responsive unitthereby between said operative and inoperative positions.
 5. Theinvention according to claim 4, and means having a source of pressureintroduced to said fluid operated ram means for moving the speedresponsive unit to the inoperative position.
 6. The invention accordingto claim 1, and said speed responsive unit comprising a centrifugalspeed responsive switch.
 7. The invention according to claim 1, and saidspeed responsive unit comprising a centrifugal speed responsive switch,generator means being operated by the movement of said car and operativeto supply a source of electrical energy to said speed control valvemeans when said centrifugal speed responsive switch closes the circuitbetween the speed responsive control valve means and the generator.
 8. Aspeed control device for a railroad car to control the speed of the carwithin predetermined limits comprising: a wheel driven means and agovernor driven by said wheel means, speed control valve means to supplyfluid under pressure to an associated car brake cylinder for operatingthe associated car wheel brakes and operatively associated with saidgovernor and opened thereby upon exceeding a predetermined maximum speedfor supplying the fluid under pressure to the brake cylinder,conditioning means operatively connected with said speed control valvemeans and the governor and selectively controlling the operation of saidvalve means in accordance with the speed of the car, off-car mountedtripping mechanism being operatively associated with said conditioningmeans to operate same and to set the conditioning means to cause asupply of pressurized fluid to said speed control valve means whenrequired, and pneumatic means including a first reservoir, a secondreservoir, passage means supplying fluid to each reservoir, conduitmeans connecting with each of the reservoirs for supplying braking fluidto the brake cylinder, said conduit means including a first conduitconnecting with the speed control valve and with the first reservoir anda second conduit connecting with the second reservoir, two-way valvemeans adapted for connecting with the associated brake cylinder andconnecting with each of the conduits, and means in said two-way valvemeans for selectively and alternately supplying communication betweenone of the conduits and the brake cylinder, said governor upon operatingof said speed control valve means allowing communication of the firstconduit with the brake cylinder and preventing communication of thesecond conduit with the brake cylinder.
 9. The invention according toclaim 8, and said two-way valve means having a port communication withthe first conduit and having a port communication with the secondconduit and having a port communication with the brake cylinder andpassage blocking means reciprocally disposed in said two-way valve andmovable in response to pressure in either the first or second conduitfor moving the passage blocking means to the other position forcommunication of the other conduit with the brake cylinder.
 10. Theinvention according to claim 8, and a quick exhaust valve being disposedbetween the speed control valve means and the two-way valve means andbleed hole means operatively associated with and operative upon thefirst conduit for dropping the pressure therein and exhausting fluidunder pressure from the associated brake cylinder and out the quickexhaust valve means.
 11. The invention according to claim 10, and saidquick exhaust valve means including a resiliently loaded diaphragmoperable to exhaust the fluid from the brake chamber upon a drop inpressure in the first conduit.
 12. A speed control device for a railroadcar to control the speed of the car within predetermined limitscomprising: a wheel driven governor, speed control valve means to supplyfluid under pressure to an associated car brake cylinder for operatingassociated car wheel brakes and operatively associated with saidgovernor and opened thereby upon exceeding a predetermined maximum speedfor supplying the fluid under pressure to the brake cylinder,conditioning means operatively connected with said speed control valvemeans and the governor and selectively controlling the operation of saidvalve means in accordance with the speed of the car, off-car mountedtripping mechanism being operatively associated with said conditioningmeans to operate same and to set the conditioning means to cause asupply of pressurized fluid to said speed control valve means when thepredetermined speed is exceeded, said speed control valve meansincluding an electrical solenoid valve and said governor including acentrifugal speed responsive switch and an electrical generator forsupplying current, the generator and switch being drivingly operated byengagement with the railroad wheel whereby an electrical current issupplied to the solenoid valve for energizing the same upon closing ofthe switch when the vehicle reaches a predetermined speed, said switchincluding a first fixed contact portion and a second movable switchportion movable toward the first fixed portion upon increase in carspeed, and means for movably adjusting the fixed contact portion withrespect to the movable portion for variably adjusting the maximum carspeed required to energize the solenoid valve.
 13. The inventionaccording to claim 12, and said variable adjustable means providing asetscrew means for movement of the fixed contact portion toward and awayfrom the movable switch portion.
 14. A speed control device for arailroad car to control the speed of the car within predetermined limitscomprising: a wheel driven governor including a speed responsive means,speed control valve means to supply fluid under pressure to anassociated car brake cylinder for operating associated car wheel brakesand operatively associated with said governor and opened thereby uponexceeding a predetermined maximum speed for supplying the fluid underpressure to the brake cylinder, conditioning means operatively connectedwith said speed control valve means and the governor and selectivelycontrolling the operation of said valve means in accordance with thespeed of the car, off-car mounted tripping mechanism being operativelyassociated with said conditioning means to operate same and to set theconditioning means to cause a supply of pressurized fluid to said speedcontrol valve means when required, a wheel driven generator, andmounting means carrying said speed responsive means and said generatorand being pivotal between an engaged position for operation of the speedcontrol device in a speed control position and in a position where saidspeed control device is inoperative.
 15. The invention according toclaim 14, and movable means connecting with the mounting means andmoving same for pivoting said generator and said speed responsive meansbetween operative aNd inoperative positions of the speed control device.16. A speed control device for a vehicle comprising: an electriccircuit, an electric generator in said circuit and for mounting on thecar and operatively connectable with the vehicle wheel and drivablethereby, a speed responsive switch in said circuit and operativelyconnectable with said wheel and drivable thereby to complete theelectric circuit to the generator in going from an open position to aclosed position when the vehicle exceeds a predetermined speed, anoff-vehicle trigger responsive switch element in said circuit havingopened and closed circuit positions and mountable on said vehicle andconnecting with the generator, a holding relay in said circuit being inseries connection with said switch element and said generator wherebywhen said switch element is in the closed position said holding relay isenergized, said holding relay being mountable on said vehicle, asolenoid actuated air valve for supplying and terminating the supply ofair pressure to the associated vehicle brakes being in said circuit andhaving a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle, said speedresponsive switch, in going from the open to the closed position uponthe vehicle''s exceeding a predetermined speed, causes the solenoidvalve to be placed in a closed circuit series connection with thegenerator with the holding relay being energized whereby the solenoidvalve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brakes, and mounting means carryingsaid speed responsive switch and said generator and being pivotalbetween an engaged position for operation of the speed control device ina speed control position and in a position where said speed controldevice is inoperative.
 17. A speed control device for a vehiclecomprising: an electric circuit, an electric generator in said circuitand for mounting on the vehicle and operatively connectable with thevehicle wheel and drivable thereby, a speed responsive switch in saidcircuit and operatively connectable with said wheel and drivable therebyto complete the electric circuit to the generator in going from an openposition to a closed position when the vehicle exceeds a predeterminedspeed, an off-vehicle trigger responsive switch element in said circuithaving opened and closed circuit positions and mountable on said vehicleand connecting with the generator, a holding relay in said circuit beingin series connection with said switch element and said generator wherebywhen said switch element is in the closed position said holding relay isenergized, said holding relay being mountable on said vehicle, asolenoid actuated air valve for supplying and terminating the supply ofair pressure to the associated vehicle brakes being in said circuit andhaving a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle, said speedresponsive switch, in going from the open to the closed position uponthe vehicle''s exceeding a predetermined speed, causes the solenoidvalve to be placed in a closed circuit series connection with thegenerator with the holding relay being energized whereby the solenoidvalve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brake means, and pneumatic meansincluding a first reservoir, a second reservoir, passage means supplyingfluid to each reServoir, conduit means connecting with each of thereservoirs for supplying braking fluid to the brake cylinder, saidconduit means including a first conduit connecting with the speedcontrol valve and with the first reservoir and a second conduitconnecting with the second reservoir, two-way valve means adapted forconnecting with the associated brake cylinder and connecting with eachof the conduits, and means in said two-way valve means for selectivelyand alternately supplying communication between one of the conduits andthe brake cylinder, said solenoid valve allowing communication of thefirst conduit with the brake cylinder and preventing communication ofthe second conduit with the brake cylinder when the vehicle exceeds thepredetermined speed.
 18. A speed control device for a vehiclecomprising: an electric circuit, an electric generator in said circuitand for mounting on the vehicle and operatively connectable with thevehicle wheel and drivable thereby, a speed responsive switch in saidcircuit and operatively connectable with said wheel and drivable therebyto complete the electric circuit to the generator in going from an openposition to a closed position when the vehicle exceeds a predeterminedspeed, an off-vehicle trigger responsive switch element in said circuithaving opened and closed circuit positions and mountable on said vehicleand connecting with the generator, a holding relay in said circuit beingin series connection with said switch element and said generator wherebywhen said switch element is in the closed position said holding relay isenergized, said holding relay being mountable on said vehicle, asolenoid actuated air valve for supplying and terminating the supply ofair pressure to the associated vehicle brakes being in said circuit andhaving a series connected with said relay and said speed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle, said speedresponsive switch, in going from the open to the closed position uponthe vehicle''s exceeding a predetermined speed, causes the solenoidvalve to be placed in a closed circuit series connection with thegenerator with the holding relay being energized whereby the solenoidvalve is moved for supplying air pressure to brake the vehicle,whereupon when the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brakes, said switch including a firstfixed contact portion and a second movable switch portion movable towardthe first fixed portion upon increase in vehicle speed, and means formovably adjusting the fixed contact portion with respect to the movableportion for variably adjusting the maximum vehicle speed required toenergize the solenoid valve.
 19. A speed control device for a vehiclecomprising: an electric circuit, an electric generator in said circuitand for mounting on the vehicle and operatively connectable with thevehicle wheel and drivable thereby, a speed responsive switch in saidcircuit and operatively connectable with said wheel and drivable therebyto complete the electric circuit to the generator in going from an openposition to a closed position when the vehicle exceeds a predeterminedspeed, an off-vehicle trigger responsive switch element in said circuithaving opened and closed circuit positions and mountable on said vehicleand connecting with the generator, a holding relay in said circuit beingin series connection with said switch element and said generator wherebywhen said switch element is in the closed position said holding relay isenergized, said holding relay being mountable on said vehicle, asolenoid actuated air valve for supplying and terminating the supply ofair pressure to the associated vehicle brakes being in said circuit andhaving a series connected with said relay and said spEed responsiveswitch and with said generator when said holding relay is energized,said solenoid valve being mountable on said vehicle, said speedresponsive switch, in going from the open to the closed position uponthe vehicle''s exceeding a predetermined speed, causes the solenoidvalve to be placed in a closed circuit series connection with thegenerator with the holding relay being energized whereby the solenoidvalve is moved for supplying air pressure to brake the vehicle,whereupon the vehicle speed falls below the predetermined speed thespeed responsive switch opens the circuit and the solenoid valve closesoff the air supply to the vehicle brakes, and mounting means for saidspeed responsive switch for attaching the speed responsive means to thevehicle, said mounting means being pivotal between an engaged positionfor operation of the speed control device in a speed control positionand having a position where said speed control device is ineffective.20. The invention according to claim 19, and means for pivotally movingsaid mounting means between operative and inoperative positions.
 21. Theinvention according to claim 20, and said means for moving including apneumatically operated ram and cylinder jack means.
 22. In a railroadvehicle having a frame structure and having ground engaging means, avehicle speed control device comprising: a ground driven generatorprovided with shaft means driven by the rotation of said ground engagingmeans, vehicle mounted solenoid operated fluid supply valve, centrifugalspeed responsive means operably engageable with said shaft means andoperable upon a predetermined rotational speed of said ground engagingmeans for operably coupling said generator with the vehicle solenoidoperated fluid supply valve for operating the latter to supply andterminate fluid under pressure to the associated vehicle brake means foroperation thereof when the predetermined speed is exceeded, startermeans operatively connected with said generator and said supply valveand operated by associated ground mounted energizing means to preparefor operation of said speed control device, and means mounted on saidvehicle frame structure and carrying said generator to and from operableengagement with said ground engaging means.
 23. The invention accordingto claim 22, and said means mounted on said vehicle frame structurefurther operatively carrying said centrifugal speed responsive means formoving said starter means from inoperable to operable position withrespect to the ground engaging means and being mounted on said vehicleframe structure.
 24. The invention according to claim 22, and saidcentrifugal speed responsive means including adjustment means forvarying the predetermined speed at which the speed responsive means isoperative.
 25. The invention according to claim 22, and said centrifugalspeed responsive means including an electrical switch being providedwith centrifugal weight means adapted to move the switch to a closedposition upon an increase in vehicle speed.
 26. The invention accordingto claim 25, and adjustment means mounted on said centrifugal switch andincluding an adjustable set member fixedly mounted on the switch and acontact portion mounted operatively with said weight means andresponsive to going into contact with said adjustable set member. 27.The invention according to claim 22, and said means mounted on thevehicle frame structure including a pivotally mounted frame carryingsaid generator in pivotal movement toward and away from said groundengaging means.
 28. The invention according to claim 27, and apneumatically operated ram unit moving said pivotally mounted frame fromoperative to inoperative position upon a change in pressure in said ramunit.
 29. The invention according to claim 28, and said centrifugalspeed responsive means being carried by said frame and being placed fromoperative to inoperative position also upon a change in presSure in saidram unit.
 30. The invention according to claim 22, and pneumatic meansfor supplying the pressure fluid to said brake cylinder including afirst reservoir for supplying fluid pressure by way of the solenoidvalve to said brake cylinder and a second reservoir for supplyingpressurized fluid to the brake cylinder via an associated second valve,flow control means in the form of a two-way valve including meansresponsive to fluid pressure from the solenoid valve or from the secondvalve to supply selectively pressurized fluid to the brake cylinder,said means including a flow blocking valve member movable in onedirection by the solenoid valve and in the other direction by the secondvalve.
 31. The invention according to claim 30, and a valve structurefor supplying the pressurized fluid to a low pressure area including ableed valve hole adjacent the solenoid valve and pressure responsivediaphragm valve movable to exhaust the air to the low pressure area whenpressurized fluid is blocked by the two-way valve between the solenoidvalve and the brake cylinder.
 32. The invention according to claim 22,and said means mounted on said vehicle frame structure comprising an armextending from said frame structure downwardly adjacent the ground, saidarm carrying at its lower end said starter means for placing the startermeans adjacent the associated ground mounted energizing means.
 33. Theinvention according to claim 32, and said starter means including amagnetically responsive switch energizable by said ground mountedenergizing means, and relay means operable upon closing of said switchto connect the generator with the solenoid operated valve when thepredetermined vehicle speed is exceeded.
 34. The invention according toclaim 1, and said mounting means having flow control means includingone-way flow means for actuation of said speed control device into anoperative position, and bleed means in said flow control means fordeactivating operation of said speed control device.
 35. The inventionaccording to claim 5, and flow control means between said ram means anda source of fluid pressure, said flow control means including a one-wayvalve permitting flow from the source of pressure to the ram means formoving said speed responsive unit to the inoperative position andincluding orifice means to allow escape of fluid under pressure fromsaid ram means to said source of pressure in the other direction toplace the speed responsive unit in the operative position.
 36. Theinvention according to claim 16, and said mounting means having flowcontrol means including one-way flow means for actuation of said speedcontrol device into an operative position, and bleed means in said flowcontrol means for deactivating operation of said speed control device.37. The invention according to claim 20, and said means for pivotallymoving said mounting means having flow control means including one-wayflow means for actuation of said speed control device into an operativeposition, and bleed means in said flow control means for deactivatingoperation of said speed control device.
 38. The invention according toclaim 21, and flow control means between said ram means and a source offluid pressure, said flow control means including a one-way valvepermitting flow from the source of pressure to the ram means for movingsaid speed responsive unit to the inoperative position and includingorifice means to allow escape of fluid under pressure from said rammeans to said source of pressure in the other direction to place thespeed responsive unit in the operative position.